Inspired by watching children play with pencils, sticks and empty spools of thread, Charles Pajeau and Robert Petit created Tinkertoy Construction Sets in 1914.

The cornerstone of the set is a wooden spool roughly two inches (5 cm) in diameter with holes drilled every 45 degrees around the perimeter and one through the center. Unlike the center, the perimeter holes do not go all the way through. With the differing-length sticks, the set was intended to be based on the Pythagorean progressive right triangle.

The sets were introduced to the public through displays in and around Chicago which included model Ferris wheels. Tinkertoys have been used to create surprisingly complex machines, including Danny Hillis's tic-tac-toe-playing computer (now in the collection of the Computer History Museum in Mountain View, California) and a robot at Cornell University in 1998.

Tinkertoys originally sold for 60¢ and were first called the 'Thousand Wonder Builder.'

The distinctive 'mailing tube' package was selected to help reduce shipping costs. The back of the package included an address label with a space for postage.

By 1918, over 2.5 million sets were sold. Up until the 1960's, the company averaged sales of over 2.5 million sets per year.

Red spools were added in 1932. Red sticks were introduced in 1953. Green, blue and yellow sticks were added in 1955.